北美空防司令部将追踪圣诞老人

rejoice– v. to feel or show that you are very happy

pandemic– n.the fast spread of an infectious disease over a very large area or the whole world

disappointment– n. a feeling of unhappiness or sadness because something did not happen as expected

location– n. a place or position

sanitize– v. to make something free from dirt or infection

app– n.(computer) short for a computer application